Katoikeo (κατοικέω) means to dwell or inhabit permanently — the kata prefix adds intensity: not temporary lodging (paroikeo) but settled, permanent residence. It is the word for God 'dwelling' in the Temple, Christ 'dwelling' in believers, and the fullness of deity 'dwelling' in Christ — all profound theological uses.
The theological summit of katoikeo is Colossians 1:19 and 2:9: 'For in him all the fullness of God was pleased to dwell' (katoikesai); 'For in him the whole fullness of deity dwells bodily' (katoikei). This is the most compact statement of Christ's full divinity in the NT: the entire fullness of the Godhead has taken up permanent residence in the body of Jesus. Ephesians 3:17: Paul prays that Christ may 'dwell in your hearts through faith' — using the same word. The Holy Spirit 'dwelling in' believers (Romans 8:11; 1 Corinthians 3:16) uses enoikeo (a related term), pointing to the same reality of divine indwelling.
The arc of redemption is the arc of katoikeo: God seeking to dwell with His people. Eden: God walking with Adam. Tabernacle/Temple: God dwelling in a sanctuary among Israel. Incarnation: the fullness of God dwelling bodily in Christ. New Creation: 'The dwelling place of God is with man' (Revelation 21:3) — permanent, unmediated, eternal habitation. We are not on a journey away from God but toward the fullness of His presence. Every prayer, every act of worship is a katoikeo — making space for the God who wants to dwell.